Files
hyperframes/packages/engine
Vance Ingalls 381887541f fix(engine,producer): fix quadratic dedup rescan, correct race justification
Address two max-effort code-review findings on PR #2056 not covered by
the earlier review-gap commit:

- captureFrameToBufferPipelined's static-dedup reuse branch never
  advanced session.lastEncodeResultFrame, unlike its sibling real-capture
  branches. The gap-check window is computed from that watermark, so
  every consecutive reuse in a static run rescanned an ever-widening
  window instead of just the newest frame — O(n^2) total work over a
  long static stretch instead of O(n).

- The "single-threaded, no race" justification on the shared
  parallelGuard closure was wrong: the guard has real internal await
  points (recapture, PSNR) between reading and writing its
  sizes/absFloor/acceptedSmall state, so concurrent workers' calls do
  interleave there (confirmed). Replaced with the actual reason it's
  safe: absFloor only ratchets down, sizes is append-only and
  order-independent for the median, and acceptedSmall's fast path
  re-validates by exact byte-equality regardless of which worker wrote
  the reference buffer.
2026-07-08 16:11:46 -07:00
..
2026-07-08 15:51:39 -07:00
2026-03-21 22:43:56 -07:00

@hyperframes/engine

Seekable web-page-to-video rendering engine built on Puppeteer and FFmpeg.

Framework-agnostic: works with GSAP, Lottie, Three.js, CSS animations, or any web content that implements the window.__hf seek protocol.

Install

npm install @hyperframes/engine

Requirements: Node.js >= 22, Chrome/Chromium (auto-downloaded by Puppeteer), FFmpeg

What it does

The engine opens your HTML composition in a headless Chrome instance, seeks frame-by-frame using Chrome's HeadlessExperimental.beginFrame API, captures screenshots, and encodes them into video with FFmpeg.

Key services

Service Description
browserManager Launches and pools headless Chrome instances (chrome-headless-shell)
frameCapture Manages capture sessions — seek, screenshot, buffer lifecycle
screenshotService BeginFrame-based capture with CDP (Chrome DevTools Protocol)
chunkEncoder FFmpeg encoding with chunked concat, GPU detection, faststart
streamingEncoder Pipe frames to FFmpeg in real time (no intermediate PNGs on disk)
audioMixer Parse <audio> elements and mix audio tracks via FFmpeg
videoFrameExtractor Extract frames from <video> elements for compositing
parallelCoordinator Split frame ranges across worker processes
fileServer Serve local HTML files to the browser via Hono

Usage

import {
  acquireBrowser,
  releaseBrowser,
  createCaptureSession,
  initializeSession,
  captureFrame,
  closeCaptureSession,
} from "@hyperframes/engine";

// 1. Launch browser
const browser = await acquireBrowser({ captureMode: "beginFrame" });

// 2. Open a capture session
const session = createCaptureSession({
  browser: browser.browser,
  url: "http://localhost:3000/my-composition.html",
  width: 1920,
  height: 1080,
  fps: 30,
});
await initializeSession(session);

// 3. Capture frames
for (let i = 0; i < totalFrames; i++) {
  await captureFrame(session, i, `/tmp/frames/frame-${i}.png`);
}

// 4. Clean up
await closeCaptureSession(session);
await releaseBrowser(browser);

Most users should use @hyperframes/producer or the hyperframes CLI instead of calling the engine directly.

Documentation

Full documentation: hyperframes.heygen.com/packages/engine